$ { {-2} \times \left[\begin{array}{rrr}{1} & {-1} & {-2} \\ {-2} & {0} & {0}\end{array}\right] = {?} } $
Solution: To multiply a matrix by a number, multiply each item of the matrix by the number. ${\left[\begin{array}{rrr}{-2}\times{1} & {-2}\times{-1} & {-2}\times{-2} \\ {-2}\times{-2} & {-2}\times{0} & {-2}\times{0}\end{array}\right]}$ Now, simplify: ${\left[\begin{array}{rrr}{-2} & {2} & {4} \\ {4} & {0} & {0}\end{array}\right]}$